The simple act of planting trees can decrease the energy you need to cool your space and lower your energy bill. Shade trees can reduce the need for air conditioning by 7 percent to 40 percent, according to research by the Department of Energy and the Sacramento Municipal Utility District. Shaded walls are 9 to 36 degrees cooler at peak temperatures. Trees raise property value and provide many other benefits. According to the U.S. Forest Service, a 1985 study estimated the values of an average 50 year old shade tree as: air conditioning worth $73, soil erosion and storm water management worth $75, wildlife shelter worth $75, and air pollution control worth $50 â a total of $273. In 1989, a total value of $57,151 was estimated for the life of a typical tree. Get the best results by planting trees to the west and southwest of buildings. Disiguous plants work well in tempered zones because they block sunlight in summer but let it in during the chilly months.